PT  - JOURNAL ARTICLE
AU  - Lisa K Stamp
AU  - Leslie G Cleland
AU  - Michael J James
TI  - Upregulation of synoviocyte COX-2 through interactions with T lymphocytes: role of interleukin 17 and tumor necrosis factor-alpha.
DP  - 2004 Jul 01
TA  - The Journal of Rheumatology
PG  - 1246--1254
VI  - 31
IP  - 7
4099  - http://www.jrheum.org/content/31/7/1246.short
4100  - http://www.jrheum.org/content/31/7/1246.full
SO  - J Rheumatol2004 Jul 01; 31
AB  - OBJECTIVE: T lymphocytes infiltrating rheumatoid synovium may alter the function of resident synoviocytes. We investigated the influence on synoviocyte cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production exerted by soluble factors released by T cells, with particular reference to interleukin 17 (IL-17). METHODS: Human peripheral blood T cells were stimulated with antibodies directed against CD3 and CD28. Harvested T cell supernatants were applied to cultured human fibroblast-like synoviocytes in culture. The effects of IL-17 alone and in combination with tumor necrosis factor-a (TNF-a) were examined using recombinant cytokines and neutralizing antibodies. Synoviocyte COX-2 expression and PGE2 production were examined. RESULTS: Supernatants from stimulated T cells upregulated COX-2 expression and increased PGE2 production by synoviocytes. The T cell supernatants were found to contain IL-17 and TNF-a. Recombinant IL-17 upregulated synoviocyte COX-2 expression and enhanced TNF-a stimulated synoviocyte COX-2 expression. The upregulation of synoviocyte COX-2 expression by supernatants from stimulated T cells was partially inhibited by addition of neutralizing antibodies against IL-17 or TNF-a or by treatment of T cells with cyclosporin A prior to stimulation. CONCLUSION: Activated T cells are capable of paracrine upregulation of synoviocyte COX-2 expression and PGE2 production through release of soluble mediators. T cell derived IL-17, especially in combination with TNF-a, may contribute to ongoing inflammation through its effects on COX-2 expression and PGE2 production. These data provide additional evidence for the contribution of T cells in rheumatoid inflammation and highlight the potential of IL-17 as a therapeutic target.